DESCRIPTION: Having cloned the gene for the Duffy protein, the Investigators propose to: 1. determine the topology of the amino and carboxyl ends by immunochemical binding or double labeling immunoelectromicroscopy (an approach that is not intuitively obvious; 2. determine the antibody and malarial binding sites on the external portion of the molecule; 3. determine the sequence of non- erythroid Duffy protein; 4. determine by immunochemistry which cells produce Duffy proteins; 5. determine the chemikine binding requirements; 6. find and clone the mouse equivalent gene; and 7. study the interactions of Duffy and Rh since a Duffy antigen (Fy5) depends upon the presence of Rh proteins for its expression. Long-term goals consist of the following: 1. determination of the function of the glycoprotein; 2. determine the significance of a Duffy like protein in the brain; 3. determine the sequence the binds to the merozoites of malaria organisms; 4. determine whether the Duffy antigen is a transporter; and 5. design mouse knock-out models to determine the significance of the Duffy protein.